Question

If f(x) = x6 - 20x5 - 20x4 - 20x3 - 20x2 – 20x - 20,
then the value of f(21) is
(2) 21
(1) 1
(3) 20
(4) 41​

Answer 1

Answer:

21 is that right or not..

Answer 2

Given:-

f(x) = x^6-20x^5-20x^4 - 20x^3 - 20x^2 -20x - 20

To find:-

Find the value of f(21)?

Solution:-

Given polynomial is

f(x) = x^6-20x^5-20x^4 - 20x^3 - 20x^2 -20x - 20

If x= 21 then

x=20+1

=>x-1 = 20

Put 20 = x-1 in above polynomial then

=>f(21)=

x^6-(x-1)x^5-(x-1)x^4-(x-1)x^3-(x-1)x^2-(x-1)x-(x-1)

=>x^6-x^6+x^5-x^5+x^4-x^4+x^3-x^3+x^2-x^2+x-x+1

f(21)=>1

Answer :-

The value of f(x) at x=21 is 1

Used formula:-

• a^m×a^n=a^(m+n)